Pneumatic tool.



PATENTED DEC. 27, 1904- v H.` LEINEWEBBR. PNEUMATIG TOOL. APPLIOATIQN FILED MAB. 19, 1904.

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Y wwe/2%?? rmavz Lez'zewege A m NQ UNITED STATES Patented December 2'7, 1904. l

PATENT OFFICE.

HERMAN Liaiivnwnnnn, or

SOUTH CHICAGO, ILLINOIS, ASSIGNOR OF PNEUMATIC TOOL.

.SPECIFICATION f-Ormingpart of Letters Patent No. 778,319, dated vDecember 27, -1904,

Y Application iiled March 19, 1904. Serial No. 199,028.

To a/ZZ whom t may concern:

Be it known that I, HERMAN LEiNEwnBnR, a citizen of the United States, residing at South Chicago, in the county of Cook and State of Illinois, have invented a new and useful Improvement in Pneumatic Tools, of which the following is a specification.

My invention relates to an improvement in the class of pneumatic hammers in which a piston confined in a casing is actuated by air.- pressure to reciprocate against a tool to drive it-such as a riveting-tool, a chisel, or the like-in the end of the casing.

The object of my invention is to providea valveless pneumatic tool in the class. referred to of simple construction, rendering it comparatively cheap to manufacture, durable, and

' reliable in operation.

lReferring, to the accompanying drawings, Figure l shows my improved pneumatic tool by a view in longitudinal sectional elevation.

Fig. 2 is a section taken at the line 2 on Fig. l

and viewed in the direction of the arrow; Fig.

3, a section taken at the line 3 on Fig. l and viewed in the direction of the'arrow; and Fig. 4 a view like that presented by Fig.` l, but showing the piston in longitudinal section.

A is the casing, of general cylindrical shape,g

having a desired tool B, (shown broken,) and which may be a riveting-tool, a chisel, or the like, seated in its distal end, with its stem CZ projecting into an enlargement forming an air-cliamber Z in the casing. site end of the casing is screwed or otherwise fastened a hollow head A, closed at its outer end, which is provided centrally on its inner;V a boss c, insuring exposure to the side with driving air-pressure of the respective end of the reciprocating piston C, hereinafter described, whenever thelatter bears against it, as when the tool is held in upright position, the head having formed with it a neck ZZ, terininating in a' handle D AVto AaY nipple e, on which is fastened the yflexible tubing (not shown) for conducting.air-pressurefrom any suitable source to the implement.v An airpassage f extends in the handle D through the neck Z and lengthwise in the wall of the On the oppo-l i ber escapes.-

head A beyond the plane of an enlargement forming an air-chamber g in the head-section of the casing. In the handle is interposed between the nipple @and the adjacent end of the passage f a spring-pressed Valve Zt, normally tending to close communication `between the nipple and passage and kcontrollable by a thumbrlever fulcrumed atm, for operating the valve to open it and admit the pressure for working the tool. The piston C is confined in the casing to reciprocate between the boss c andthe end of the tool-stem a. -It is closed at both ends and contains a desired number (one ormore) of longitudinal ducts 7c, each terminating at its opposite ends, respectively, in lateral openings Zn and 762 in the piston near its ends. The passage f leads -to a series `of ports f', extending transversely through the casing, these ports communicating with branches f2 of the passage f, extending lengthwise in the ywall of the casing, and` these branches terminate at an annular enlargement forming the pressure-feeding chamber Z inthe casing between the chambers Z and getherein. Exhaust-ports are provided in the casing at m and n.

The operationv is as follows, with the parts in the relative positions in which they are shown in the drawings: On pressing the lever to opeii'the Valve ZL air-pressure flows through the passage f, openings f', and bran'c'hesf2 into the feeding-chamber Z, whence it enters the piston-opeiiings 7a2 and passes through the Vpiston-ducts Zn, discharging therefrom at the openings Ze into the chamber g, wherein it acts against the end of the piston therein and drives the latter against. the stem a. At the end of that (the forward) stroke of the piston the openings in thereinl are within the chamber Z,-thereby leaving the chamber g open through the piston-way to the exhaust-port n, through which the pressure from thatcham- This position of the piston brings the openings Ze into the chamber Z, (constantly, -while the valve /L is held open, supplied with air-pressure from the'branches f2, which are "in open communication through the ports f with the passage f,) and pressure from that chamber enters the openings Zn', passes through the piston-duets and discharges from the latter at the piston-openings k2 into the chamber b, wherein it acts against the respective end of the piston to produce its back stroke, in making which it uncovers the exhaust-port m, permitting the pressure in the chamber b to escape therefrom, and at the end of which the piston-openings k2 are again in the feeding-chamber Z to admit therefrom through those openings and the ducts 7n and openings c,'then in the chamber g, air-pressure into the latter for effecting the forward or driving stroke of the piston. In this manner the piston is reeiprocated with great rapidity to act against the tool B.

It will be noticed that the chamber g is larger than the chamber b. The purpose of this difference is to cause the air-pressure force for the forward piston-stroke to be greater than that for producing the back stroke and to reduce to the minimum the recoil in the chamber g.

The gist of my invention consists in providing the intermediate pressure-feeding chamber in communication with a pressure-supply passage and the piston containing one or more air-ducts opening alternately into the feedingchamber at the ends of the successive pistonstrokes with exhaust-equipped end chambers, into which the driving-pressure enters alternately from the feeding-chamber through the piston. Hence I do not limit my invention to the details of construction and combinations of parts shown and described, since they may be variously modified without departure from the invention.4

What I claim as new, and desire to secure by Letters Patent, is-

l. In a pneumatic tool having a easing carrying at one end the tool and at its opposite end a handle, the combination with the easing of a Valve-controlled air-pressure-supply passage, end chambers and an intermediate feeding-chamber for the air-pressure in the casing, said feeding chamber communicating with said passage, a piston reeiproeably confined in the casing, having one or more ducts each terminating at its ends in lateral openings in the piston, whereby at the end of each pistonstrolie the opening or openings register with said feeding-chamber, and exhaust-ports in the easing for said end chambers.

2. In a pneumatic tool having a casing carrying at one end the tool and at its opposite end a handle, the combination with the easing of a valve-controlled air-pressure-supply passage, end chambers and an intermediate feeding-chamber for the air-pressure in the casing, said feeding-chamber communicating with sald passage, an exhaust-port adjacent to each end chamber, and a piston reciprocably confined in the casing, having closed ends and a plurality of longitudinal ducts within it ,each terminating at its ends in lateral openings in the piston, near its ends, said openings near the respective piston ends registering alternately with said feeding-chamber at the ends of the successive piston-strokes.

3. In a pneumatic tool having a casing earrying at one end the tool and at its opposite end a handle, the combination with the easing of a valve-controlled air-pressure-supply passage terminating in the casing-wall and having branches communicating therewith, end chambers in the casing and an intermediate pressure-feeding chamber therein to which said branches discharge, an exhaust-port adjacent to each end chamber, and a piston reciprocably confined in the casing, having closed ends and containing a plurality of longitudinal ducts each terminating at its ends in openings in the piston near its ends, said openings near the respective piston ends registering alternately with said feeding-chamber at the ends of the successive piston-strokes.

4. In a pneumatic tool the combination of a casing carrying at one end the tool and provided on its opposite end with a head having formed with it a neck and a handle, pressurechambers in the easing near its opposite ends each provided with an exhaust-port and an intermediate pressure-feeding chamber therein, a passage for the air-pressure leading through said handle and neel: and terminating in the wall of said head, branches extending in the casing-wall from said passage and discharging into said feeding-chamber, a spring-pressed valve in said passage in the handle provided with an operating-lever, and a piston reciprocably confined in the casing, having closed ends and containing longitudinal ducts each terminating' at its ends in openings in the piston near its ends, said openings near the respective piston ends registering alternately with said feeding-chamber at the ends of the successive piston-strokes.

5. In a pneumatic tool, the combination with the casing containing a pressure-eliamber in each end portion, and an air-pressure-supply passage, of a piston reciprocably confined in the casing, having closed ends with one or more duets extending lengthwise within it and each terminating at its opposite ends in lateral openings in the piston, whereby the air-pressure for driving the piston may beintroduced through it to act against its respective ends.

HERMAN LEINE\VEBER.

In presence of- F. M. VViR'r@ WALTER N. WINBERG.

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